Echogenic intracardiac focus on second trimester ultrasound: prevalence and significance in a Middle Eastern population

Objective: The association between echogenic intracardiac focus (EIF) and trisomy 21 is well established, with a recognized ethnic variation. Our study aimed to determine the prevalence of EIF in a Middle Eastern population and to examine its association with trisomy 21 and other adverse pregnancy outcomes.

Methods: Retrospective case-control study of second-trimester obstetric sonograms (16–28 weeks) performed at a tertiary care center over a 5-year period. Cases with EIF were retrieved, and a matched control group with no EIF was identified. The incidence of trisomy 21 and other adverse pregnancy outcomes was compared.

Results: A total of 9270 obstetric sonograms were examined, with an EIF prevalence of 2.5% (95% CI: 2.2–2.8%). Of patients with available outcome data, EIF was not associated with trisomy 21 (0/163 versus 1/163; p value = 1.00). Additionally, EIF was not associated with trisomy 18, trisomy 13, small for gestational age, preterm birth, fetal demise, cesarean delivery, operative vaginal delivery, or admission to the neonatal intensive care unit.

Conclusion: In a contemporary Middle Eastern population, EIF is a rare occurrence. As an isolated finding, it is not associated with aneuploidy or other adverse pregnancy outcomes. EIF appears to be incidental with no impact on clinical practice.     

Spatio-temporal image correlation (STIC) as a new screening tool for prenatal detection of congenital heart defects. The first Spanish experience

Introduction. The recent introduction of three- and four-dimensional ultrasonography opens a promising perspective in prenatal diagnosis.

Objective. To assess the use of the STIC technique as a screening tool in order to perform a “basic and extended fetal cardiac evaluation”.

Methods and material. A number of volumes are prospectively obtained during the routine morphological scan by a general sonographer in 28 patients randomly selected among those attending our unit. Afterwards, an experimented examiner in fetal echocardiography proceeds to their offline analysis. The successful rate of volume acquisition and analysis is evaluated, as well as the percentage of cases in which a “basic” or “extended” cardiac evaluation is possible through single sweep and multiplanar navigation. Cases with chromosomal anomalies, cardiac abnormalities or extracardiac malformations are excluded.

Results. A number of 58 volumes are included, with gestational ages ranging between 17 and 35 weeks. STIC acquisition was possible in all cases. A “basic cardiac study” was achieved in 100% of cases, while an “extended cardiac study” was achieved in 86% of them. Multiplanar study improved the visualization of those structures not identifiable through the initial acquisition single plane in all cases.

Conclusions. We present the first study on a nationwide scale about the introduction and applications of the STIC technology. STIC volumes can be obtained by operators inexperienced in fetal echocardiography and their offline analysis enables recognition of most of the structures and views necessary to assess fetal cardiac anatomy.     

An isolated intracardiac echogenic focus as a marker for aneuploidy

OBJECTIVE: This study was undertaken to evaluate the relationship of an isolated fetal intracardiac echogenic focus in a population of patients with a mixed risk for aneuploidy when presenting for prenatal diagnosis. STUDY DESIGN: All women referred to our institution for screening ultrasound were prospectively evaluated for the presence of an intracardiac echogenic focus in the fetal heart. Each patient was evaluated for the presence of clinical risk factors including ultrasound findings, biochemical screening, and maternal age. The population of patients was then described and neonatal outcomes were obtained. RESULTS: A total of 10,875 patients were referred and 176 cases of fetal intracardiac echogenic foci were evaluated. There was an overall prevalence of 1.6% in our population. The patients with other ultrasound findings and/or maternal age older than 35 years who underwent amniocentesis had 3 abnormal karyotypes identified and had identifiable risk factors. In the group less than 35 years, the relative risk was 2.55 of having an amniocentesis for an isolated echogenic focus (with no cases of fetal aneuploidy found) in comparison with our referred group of nonadvanced maternal age patients without any ultrasound markers or findings. CONCLUSION: This isolated echogenic finding appears to be a benign variant and not an increased risk for fetal aneuploidy. The chromosomal abnormalities were seen in the group with risk factors including maternal age and/or other ultrasound findings. Evaluation of maternal age, biochemical markers, and ultrasound markers should be used together to help determine the risk of patients with an isolated echogenic focus.     

An ethnic predilection for fetal echogenic intracardiac focus identified during targeted midtrimester ultrasound examination: A retrospective review

Background  

Echogenic intracardiac focus (EIF) has been identified as a common ultrasound finding in association with fetal aneuploidy. Little is known about the association of this soft marker aneuploidy in various ethnic groups. Although it is commonly thought Asians in general have a higher incidence of EIF, it is unknown whether this also applies to Japanese as a subpopulation. The purpose of this study is to determine the antenatal incidence and postnatal significance of EIF observed during sonography in Japanese patients.     

Frequency of echogenic intracardiac focus by race/ethnicity in euploid fetuses.

OBJECTIVE: To determine the frequency of echogenic intracardiac focus (EIF) by race/ethnicity. METHODS: We performed a retrospective analysis from January 1996 through June 2003. We reviewed all initial sonograms from 14 to 23 weeks gestation in singleton pregnancies. Mothers on admission for delivery provided race/ethnicity. RESULTS: There were 8207 ultrasounds and deliveries that met study criteria. There were 4636 (56.5%) Caucasian, 2087 (25.4%) African-American, 1261 (15.4%) Hispanic and 223 (2.7 %) Asian subjects. There were 347 (4.2%) EIF detected. The frequency by race/ethnicity varied significantly (p < 0.0001). CONCLUSIONS: This large, population-based study showed that fetuses born to Asian mothers were significantly more likely to have an EIF. This racial difference should be taken into account when counseling patients about the potential for Down syndrome.     

Ultrasound tissue characterization with the gray level histogram width of the B-mode

Objectives. We investigated fetal lung immaturity, fetal brain periventricular echodensity (PVE) and other problems related to changes in fetal tissue by non-invasive ultrasound tissue characterization, using a commonly available real-time B-mode ultrasound machine.

Methods. Histograms of a region of interest (ROI) were displayed on a B-mode screen. The base length of a histogram divided by the full gray-scale length gave the gray level histogram width (GLHW); this value is insensitive to changes in B-mode model, device gain or image depth. Any variation in the magnitude of GLHW in high-contrast images was easily corrected. Fetal lung immaturity was suspected when the fetal lung GLHW was less than that of normal fetal lung and fetal liver after 30 weeks of pregnancy. The GLHW values of fetal brain PVE were also compared to those of normal fetal brain.

Results. GLHW values were compared between the “mature fetal lung” and the “immature fetal lung” groups, as determined by the stable microbubble test: the former had 5 or more microbubbles per 1 mm² of aspirated and shaken amniotic fluid on microscopic observation, while the latter had less than 5. The sensitivity and specificity of the GLHW criterion in predicting lung immaturity were 89% and 79%, respectively, when the GLHW was less than 31%, and less than that for fetal liver. The GLHW of fetal brain PVE was significantly higher than that of normal fetal brain. The GLHW was also high in various obstetrical abnormalities and in the case of malignant gynecological masses.

Conclusion. The GLHW of B-mode images from simple real-time ultrasound imaging machines is useful for the characterization of fetal tissue.     

Isolated echogenic intracardiac foci in patients with low-risk triple screen results: assessing the risk of trisomy 21

OBJECTIVE: While an echogenic intracardiac focus (EIF) is associated with an increased risk of trisomy 21 (T21), the magnitude of that risk remains controversial, particularly in the setting of a low-risk triple screen (TS). The objective of this study is to define the risk of T21 in patients with a low-risk TS and an isolated EIF. STUDY DESIGN: A retrospective analysis was performed on patients presenting prior to 22 6/7 weeks of gestation. Patients met criteria for inclusion if an EIF was noted, a TS had been drawn, the anatomic survey was complete and was determined to be normal, and karyotyping or delivery occurred at Bellevue Hospital. A high-risk TS was defined as a risk of <1:500, assuming a 2-fold increased risk in the setting of an isolated EIF. A low-risk TS was defined as a risk of >1:500. Statistical analysis was performed using chi-square, with p values of <0.05 considered significant. RESULTS: 7,318 anatomic surveys were performed. An EIF was identified in 584 patients (7.98%), of which 391 met the criteria for inclusion. Of the 391, 51% were Asian and 38% were Hispanic; 348 had a low-risk TS and 43 had a high-risk TS. Patients with an EIF and a low-risk TS had a significantly lower risk of having a T21 pregnancy compared to those with a high-risk TS and an EIF (0 vs. 2.3%; p = 0.004). CONCLUSION: An isolated EIF with a low risk TS is not associated with an increased risk of T21.     

The impact of the use of the isolated echogenic intracardiac focus as a screen for Down syndrome in women under the age of 35 years.

OBJECTIVE: The purpose of this study was to determine the public health impact of the routine offering of amniocentesis to women under the age of 35 years who have an isolated fetal echogenic intracardiac focus on second trimester ultrasound scan. STUDY DESIGN: A decision analytic model was designed that compared the accepted standard of second trimester triple marker screen for Down syndrome to a policy in which amniocentesis with an isolated echogenic intracardiac focus on ultrasound in addition to the triple marker screen is offered to all women in the United States who are <35 years of age. A sensitivity of 20%, an echogenic intracardiac focus screen positive rate of 5%, and a risk of Down syndrome of 1:1000 were assumed. A sensitivity analysis was performed that varied the screen positive rate, the sensitivity of echogenic intracardiac focus for Down syndrome, and the prescreen risk for Down syndrome in the population. RESULTS: With the baseline sensitivities, rates, and risks, the use of isolated echogenic intracardiac focus as a screen would result in an additional 118,146 amniocenteses performed annually to diagnose 244 fetuses with Down syndrome. These amniocenteses would result in 582 additional miscarriages. It would be necessary to perform 485 amniocenteses that would result in 2.4 procedure-related losses for each additional Down syndrome fetus that was identified. CONCLUSION: Although the echogenic intracardiac focus appears to be associated with a small increased risk of Down syndrome, its use as a screening tool in low-risk populations would lead to a large number of amniocenteses and miscarriages to identify a small number of Down syndrome fetuses.     

Meta-analysis of validity of echogenic intracardiac foci for calculating the risk of Down syndrome in the second trimester of pregnancy

Echogenic intracardiac foci are a second trimester marker associated with aneuploidy in high-risk populations. The objective of this study is to assess the validity of echogenic intracardiac foci for Down syndrome detection in the second trimester ultrasound scan. A systematic search in major bibliographic databases was carried out (MEDLINE, EMBASE, CINAHL). Twenty-five studies about echogenic intracardiac foci were selected for statistical synthesis in this systematic review. Those 25 considered to be relevant were then subjected to critical reading, following the Critical Appraisal Skills Programme criteria, by at least three independent observers. Then, the published articles were subjected to a meta-analysis. A global sensitivity of 21.8% and a 4.1% false positive rate were obtained. The positive likelihood ratio was 5.08 (95% confidence interval, 4.04–6.41). The subgroups analysis did not reveal statistically significant differences. In conclusion, echogenic intracardiac foci as an isolated marker could be a tool to identify—rather than exclude—the high-risk group of Down syndrome, although it should be noted that it shows low sensitivity.     

Ultrasound markers for Down syndrome

Trisomy 21 (Down syndrome) is the most common chromosomal abnormality. Sonographic findings in fetuses with Down syndrome include both structural abnormalities and nonstructural abnormalities or "markers." These markers are known as "soft markers" of aneuploidy. These markers are nonspecific, often transient. The most commonly studied soft markers of aneuploidy include a thickened nuchal fold, long bones shortening, mild fetal pyelectasis, echogenic bowel, echogenic intracardiac focus, FMF angle > 90 degrees, pathologic velocity of Ductus venosus and choroid plexus cyst.     

Isolated Intracardiac Echogenic Focus on Routine Ultrasound: Implications for Practice

Ultrasound is widely used as a screening tool for fetal anomalies. An intracardiac echogenic focus (ICEF) is associated with fetal aneuploidy, particularly trisomy 21, when found with other minor abnormalities known as soft markers. However, when found in isolation, intracardiac echogenic foci are morphologic variations with little or no pathologic significance for the fetus. Ambiguity about the significance of ICEF and other soft markers and the lack of preparation prior to ultrasound can result in unnecessary worry for women and their partners. A variety of tools exist that providers can use to help pregnant women and their partners make informed decisions about ultrasound and fetal screening.     

Ultrasonographic soft markers of aneuploidy in second trimester fetuses

ObjectiveTo evaluate ultrasound “soft markers” used in fetal genetic screening.OptionsUltrasound screening at 16–20 weeks is one of the most common genetic screening tests used during pregnancy. The practical concern for ultrasound screening is false-positive and false-negative results. The use and understanding of ultrasound soft markers and their screening relative risks are an important option in the care of pregnant women.IntroductionChromosomal abnormalities occur in 0.1–0.2% of live births, and the most common clinically significant aneuploidy among live-born infants is Down’s syndrome (trisomy 21). Soft markers of aneuploidy are nonspecific, often transient, and can be readily detected during the second and third trimester ultrasound. The most commonly studied soft markers of aneuploidy include a thickened nuchal fold, mild fetal pyelectasis, echogenic bowel, echogenic intracardiac focus and choroid plexus cyst. There is a great deal of interest in the ultrasound detection of aneuploidy, as evidenced by the large number of publications in the literature on this topic.     

Time to reconsider our approach to echogenic intracardiac focus and choroid plexus cysts

Ultrasound soft markers are commonly reported at mid-trimester ultrasounds. Soft markers frequently arouse anxiety in the patient, her family, and the referring clinician. Recent publications have raised concerns that this anxiety may be unfounded. The significance of an echogenic intracardiac focus or choroid plexus cyst in particular is no longer certain. It may be time to discard these two markers; especially if they are reported in isolation and in a patient who is otherwise at low risk for aneuploidy.     

Sonographic determination of gestational age

Objective.To review current evidence regarding sonographic determination of gestational age.

Methods.We reviewed current and available data to evaluate optimal methods of gestational age determination.

Results.First trimester estimates of gestational age based on crown-rump length and second trimester estimates of gestational age based on composite biometry are very accurate with an absolute error of less than 5 days in the first trimester and 7 days in the second trimester in most cases.

Conclusion.Ultrasound is an accurate and useful modality for assessment of gestational age in the first and second trimester of pregnancy and, as a routine part of prenatal care, can greatly impact obstetric management and improve antepartum care.     

Fetal circulation and placental blood flow in monochorionic twins

Objectives. Twin to twin transfusion syndrome (TTTS) is one of the most important problems for perinatal management of monochorionic twins. Since TTTS is deeply related to the prognoses of both fetuses, fetal circulation and placental blood flow of monochorionic twins were studied with the purpose of clarifying characteristic features.

Methods. The patterns and numbers of vascular anastomoses were checked on the placental surface, arterio-arterial (A-A) anastomosed vessels by ultrasound, and circulatory changes were studied with relation to uterine contraction.

Results. The high risk of monochorionic twin pregnancies was largely related to the patterns of vascular anatomy of the placenta and numbers of anastomosed vessels. The first placental vascular connection detected in vivo was the A-A anastomosis characterized by the bidirectional flow waveform in pulsed Doppler velocimetry.

Conclusion. TTTS is related to anastomosed vessels on the surface of placenta. To manage and prevent TTTS, fetal circulation and placental blood flow should be carefully observed.     

Fetal nasal bone as ultrasonographic marker for trisomy 21 in a low-risk population between 18 and 22 gestational weeks

Objective. The aim of this article is to evaluate the role of the fetal nasal bone as a marker for trisomy 21 in prenatal diagnostic ultrasound (18-22 weeks) in the general population and to establish the reference values for nasal bone length at this gestational stage.

Subjects and methods. The nasal bone length was determined in 7054 consecutive fetuses among our general population who underwent the prenatal diagnostic ultrasound (18-22 weeks). Of this sample, 20 fetuses had trisomy 21. For each gestational week, the 2.5, 5, 50, 75, and 95 percentiles, mean, and standard deviation were determined.

Results. The exam was satisfactory in 6972 out of 7054 (98.8%) cases. Hypoplastic nasal bone (less than 2.5 percentile for the gestational age) was found in 11 out of 20 (55%) fetuses with trisomy 21 and in 124 out of 6952 (1.8%) normal fetuses. The measurement of nasal bone resulted in an increase in sensitivity of the second trimester screening from 14% to 43%. Tables were elaborated with reference lengths for each gestational age.

Conclusion. The detection of nasal bone hypoplasia (nasal bone absent or below the 2.5 percentile) results in an increase in sensitivity in the screening for trisomy 21 in the second trimester ultrasound in a low-risk population.     

The association of maternal BMI with fetal echogenic intracardiac foci and echogenic bowel

Objectives.?To evaluate the impact of maternal body mass index (BMI) as well as maternal ethnicity on the detection of either echogenic intra-cardiac focus (EIF) or echogenic bowel (EB).

Methods.?This prospective study identified 74 uncomplicated singleton fetuses in which EIF and/or EB were detected between 18 and 21 weeks of gestation (i.e. study group). Seventy four consecutively scanned fetuses without EIF or EB, at the same gestational age, were selected as controls. The differences in maternal BMI and maternal ethnicity were compared between the two groups using the χ² test, Fisher's exact test, and the Student t-test. A multivariable logistic regression model was constructed to control for confounders. Odds ratios (OR) and their 95% confidence interval (CI) were computed.

Results.?The mean maternal BMI was significantly lower in the study group as compared to controls (22.9?±?3.1 vs. 28.0?±?7.5?kg/m², respectively; p?<?0.0001). Patients with fetal EIF and/or EB were significantly more likely to be Asians (20.3% vs. 5.4%, OR?=?4.5; 95% CI 1.3–16.9). Using a multivariable analysis, controlling for ethnicity, the association between maternal BMI and fetal EIF or EB remained significant (OR?=?0.83; 95% CI 0.76–0.91). However, based on this model Asian ethnicity was not an independent risk factor for the detection of EIF and/or EB (OR?=?2.6; 95% CI 0.8–8.9).

Conclusions.?Our data suggests an inverse relationship between the maternal BMI and the detection of fetal EIF and/or EB. Moreover, it appears that low maternal BMI, and not Asian ethnicity, is an independent risk factor for the detection of these echogenic fetal findings.     

Isolated fetal echogenic intracardiac foci or golf balls: is karyotyping for Down's syndrome indicated?

Objective To determine the prevalence of isolated echogenic intracardiac foci and the subsequent risk for Down's syndrome at 18–23 weeks in an unselected obstetric population.
Design Prospective study.
Setting A district general hospital serving a routine obstetric population.
Participants 16,917 pregnant women who underwent a routine ultrasound screening at 18–23 weeks of gestation between November 1994 and August 1998.
Methods All women were offered screening for Down's syndrome by nuchal translucency or maternal serum biochemistry. The prevalence of isolated echogenic intracardiac foci was determined and the relative risk for Down's syndrome was calculated for different ultrasound findings.
Results The combined sensitivity of age, nuchal translucency and maternal serum biochemistry for Down's syndrome was 84% (27/32). The relative risk for Down's syndrome was 0.17 (95% CI 0.07–0.41) for the women with normal scan findings at 18–23 weeks. The prevalence of isolated echogenic intracardiac foci at 18–23 weeks was 0.9% (144/16,917). None of these pregnancies were affected by Down's syndrome.
Conclusion The significance of the association between isolated echogenic intracardiac foci and Down's syndrome is a matter of ongoing debate. The data of this study suggest that in an unselected obstetric population with prior, effective, routine Down's syndrome screening, the association between isolated echogenic intracardiac foci and Down's syndrome is no longer significant.     

Chromosomal and cardiac anomalies in fetuses with intracardiac echogenic foci.

OBJECTIVE: To evaluate the prevalence of intracardiac echogenic foci (ICEF) and the association between ICEF and chromosomal and cardiac anomalies in Brazilian women. METHODS: In a cross-sectional observational study, 373 of the 23,360 genetic sonograms performed at a private maternal-fetal medicine clinic over 5 years showed intracardiac echogenic foci (ICEF). These 373 sonograms were reviewed for chromosomal and cardiac anomalies and associations were analyzed using the chi(2) test or the Fisher exact test. P<0.05 was considered significant. RESULTS: The prevalence of ICEF was 1.7%. Cardiac anomalies were detected in 10 sonograms (2.7%) and chromosomal anomalies in 14 (3.7%). There were cardiac defects in 6 (1.7%) of the 359 euploid fetuses with isolated ICEF. Of the 373 women who had fetuses with ICEF, 295 were younger than 35 years and 78 were 35 years or older. There were 6 fetuses (2.1%) with aneuploidy in the younger group and 8 (10.3%) in the older group. CONCLUSION: The prevalence of ICEF was 1.7%, and there was an association between cardiac and chromosomal anomalies. Women carrying fetuses with ICEF should be offered fetal echocardiography and karyotyping.     

Isolated fetal echogenic intracardiac foci or golf balls: is karyotyping for Down's syndrome indicated?

OBJECTIVE: To determine the prevalence of isolated echogenic intracardiac foci and the subsequent risk for Down's syndrome at 18-23 weeks in an unselected obstetric population. DESIGN: Prospective study. SETTING: A district general hospital serving a routine obstetric population. PARTICIPANTS: 16,917 pregnant women who underwent a routine ultrasound screening at 18-23 weeks of gestation between November 1994 and August 1998. METHODS: All women were offered screening for Down's syndrome by nuchal translucency or maternal serum biochemistry. The prevalence of isolated echogenic intracardiac foci was determined and the relative risk for Down's syndrome was calculated for different ultrasound findings. RESULTS: The combined sensitivity of age, nuchal translucency and maternal serum biochemistry for Down's syndrome was 84% (27/32). The relative risk for Down's syndrome was 0.17 (95% CI 0.07-0.41) for the women with normal scan findings at 18-23 weeks. The prevalence of isolated echogenic intracardiac foci at 18-23 weeks was 0.9% (144/16,917). None of these pregnancies were affected by Down's syndrome. CONCLUSION: The significance of the association between isolated echogenic intracardiac foci and Down's syndrome is a matter of ongoing debate. The data of this study suggest that in an unselected obstetric population with prior, effective, routine Down's syndrome screening, the association between isolated echogenic intracardiac foci and Down's syndrome is no longer significant.